Targeting NEDD9-SH3 with a Covalent Peptide Controls Endothelial Phenotype

Area of Science:

• Biochemistry
• Molecular Biology
• Pharmacology

Background:

• Src homology 3 (SH3) proteins are implicated in fibroproliferative diseases like pulmonary arterial hypertension (PAH).
• Targeting SH3 proteins therapeutically presents significant challenges.
• Neural precursor cell expressed, developmentally down-regulated 9 (NEDD9) is a pro-PAH regulator containing an SH3 domain.

Purpose of the Study:

• To develop a novel peptidomimetic targeting the SH3 domain of NEDD9.
• To investigate the therapeutic potential of NEDD9 inhibition in pulmonary arterial hypertension (PAH).
• To elucidate the mechanisms by which NEDD9 influences endothelial cell phenotype and vascular remodeling.

Main Methods:

• Design and synthesis of a bromoacetamide-derivatized peptidomimetic targeting NEDD9's FAK binding site.
• Assessment of peptidomimetic effects on human pulmonary artery endothelial cell (HPAEC) migration and FAK binding.
• Investigation of NEDD9 and sulfatase-1 (SULF1) interactions using siRNA and overexpression studies.
• Evaluation of therapeutic efficacy in a rodent model of PAH.

Main Results:

• The peptidomimetic covalently bound to NEDD9 (Cys18), inhibiting FAK binding and HPAEC migration.
• NEDD9 inhibition, via siRNA or peptidomimetic, downregulated SULF1, promoting podosome formation and migration.
• Sulfatase-1 knockdown prevented PAH-related vascular remodeling and reversed pulmonary hypertension in vivo.
• The developed therapeutic approach demonstrated efficacy in reversing established PAH.

Conclusions:

• A structure-validated covalent peptidomimetic targeting the NEDD9 SH3 domain was successfully developed.
• NEDD9 regulates endothelial cell phenotype and vascular remodeling through convergent mechanisms involving sulfatase-1.
• This study establishes a novel SH3-specific therapeutic strategy for PAH and other fibroproliferative disorders.